Emerging 5G wireless systems are designed to support high-bandwidth and low-latency networks that connect everything from autonomous robots to self-driving cars. But these large and complex communication networks may also bring new security issues.
Current encryption methods used to protect eavesdroppers’ communications may be difficult to extend to such high-speed and ultra-low-latency systems of 5G and higher. This is because the nature of encryption requires the exchange of information between the sender and receiver to encrypt and decrypt messages. This exchange makes the link vulnerable to attack; it also requires calculations that increase latency. Latency, the amount of time between sending instructions on the network and the arrival of data, is a key measure of tasks such as autonomous driving and industrial automation. For networks that support latency-critical systems, such as self-driving cars, robots, and other cyber-physical systems, minimizing action time is critical.
To bridge this security gap, researchers at Princeton University have developed a method that incorporates security into the physical properties of the signal.In a report published on November 22 Natural electronics, The researchers described how they developed a new millimeter-wave wireless microchip that allows secure wireless transmission to prevent interception without reducing the latency, efficiency, and speed of 5G networks. According to senior researcher Kaushik Sengupta, this technology should make eavesdropping on such high-frequency wireless transmissions very challenging, even if there are multiple bad guys in collusion.
“We are in a new era of wireless-the future of networks will become more and more complex, while serving a large number of different applications, these applications require very different functions,” Sengupta said. “Think about low-power smart sensors in the home or industry, high-bandwidth augmented reality or virtual reality, and self-driving cars. To meet this and serve this well, we need to consider safety as a whole and at all levels. sex. “
The Princeton method does not rely on encryption, but instead shapes the transmission itself to deter potential eavesdroppers. To explain this, it helps to describe the wireless transmission that emerges from the antenna array. For a single antenna, radio waves radiate from the antenna in the form of waves. When there are multiple antennas working as an array, these waves will interfere with each other like water waves in a pond. Interference increases the size of some crests and troughs and smoothes other crests and troughs.
The antenna array can use this interference to guide transmission along a defined path. But in addition to the primary transmission, there are also secondary paths. These secondary paths are weaker than the primary transmission, but in a typical system, they contain exactly the same signals as the primary path. By eavesdropping on these paths, a potential eavesdropper can disrupt the transmission.
Sengupta’s team realized that they could thwart an eavesdropper by making the signal at the eavesdropper’s location look almost like noise. They do this by randomly splitting the message and assigning different parts of the message to a subset of antennas in the array. Researchers can coordinate transmissions so that only receivers in the intended direction can combine the signals in the correct order. Anywhere else, the chopped signal arrives in a noise-like manner.
Sengupta likens this technique to cutting a piece of music in a concert hall.
“Imagine in a concert hall, when playing Beethoven’s Ninth Symphony, each instrument, instead of playing all the notes of the music, decides to play randomly selected notes. They play these notes at the right time, and at the right time. Keep silent in between, for example, each note in the original song is played by at least a certain instrument. When the sound waves carrying these notes pass through the hall from all the instruments, at a certain location, they can arrive precisely in the correct way. Listen. The person sitting there will enjoy the original song, as if nothing has changed. Others will hear the noise of missing notes arriving randomly, almost like noise. In principle, this is the secret weapon behind transmission security-by precise space Realization and time modulation of these high-frequency electromagnetic fields.”
If an eavesdropper attempts to intercept the message by interfering with the main transmission, it will cause transmission problems and be detected by the intended user. Although it is theoretically possible for multiple eavesdroppers to work together to collect noise-like signals and try to reassemble them into coherent transmissions, Sengupta said the number of receivers needed to do so would be “very large.”
“We showed for the first time that we can use artificial intelligence to collude with eavesdroppers to splice several noise-like signatures into the original signal, but this is very challenging. We also showed how the transmitter can trick them. It is one Cat-mouse game.”
Edward Knightly, a professor at Rice University who was not involved in the study, said that Sengupta’s work is “an important milestone” in protecting the future network.
“For the first time, he demonstrated through experiments how to use machine learning data collected from multiple simultaneous observation points to overcome even a complex opponent,” he said.
The team created the entire end-to-end system in silicon chips manufactured through standard silicon foundry processes.
Sengupta said that encryption can also be used with the new system to improve security. “You can still encrypt on top of it, but you can reduce the burden of encryption with an additional layer of security,” he said. “This is a free method.”
Safe air-conditioning millimeter wave wireless link to resist distributed eavesdropping attacks Published on Nature Electronics on November 22. In addition to Sengupta, the authors also include postdoctoral scholar Suresh Venkatesh, Princeton University graduate student Lu Xuyang, and Princeton University visiting researcher Tang Bingjun. Part of the support for this project is provided by the Air Force Office of Scientific Research, the Office of Naval Research, the Office of Army Research, the DURIP Fund, and the Defense Advanced Research Projects Agency.
